MySQL 8.4.3
Source Code Documentation
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#include <field.h>
Public Member Functions | |
Field_blob (uchar *ptr_arg, uchar *null_ptr_arg, uchar null_bit_arg, uchar auto_flags_arg, const char *field_name_arg, TABLE_SHARE *share, uint blob_pack_length, const CHARSET_INFO *cs) | |
Field_blob (uint32 len_arg, bool is_nullable_arg, const char *field_name_arg, const CHARSET_INFO *cs, bool set_packlength) | |
Field_blob (const Field_blob &field) | |
Copy static information and reset dynamic information. More... | |
Field_blob (uint32 packlength_arg) | |
enum_field_types | type () const override |
bool | match_collation_to_optimize_range () const override |
enum ha_base_keytype | key_type () const override |
type_conversion_status | store (const char *to, size_t length, const CHARSET_INFO *charset) override |
type_conversion_status | store (double nr) override |
Store double value in Field_string or Field_varstring. More... | |
type_conversion_status | store (longlong nr, bool unsigned_val) override |
type_conversion_status | store (const Field *from) |
double | val_real () const override |
longlong | val_int () const override |
String * | val_str (String *, String *) const override |
my_decimal * | val_decimal (my_decimal *) const override |
int | cmp_max (const uchar *, const uchar *, uint max_length) const final |
int | cmp (const uchar *a, const uchar *b) const final |
int | cmp (const uchar *a, uint32 a_length, const uchar *b, uint32 b_length) const |
int | cmp_binary (const uchar *a, const uchar *b, uint32 max_length=~0L) const override |
int | key_cmp (const uchar *, const uchar *) const override |
int | key_cmp (const uchar *str, uint length) const override |
uint32 | key_length () const override |
size_t | make_sort_key (uchar *buff, size_t length) const override |
Writes a copy of the current value in the record buffer, suitable for sorting using byte-by-byte comparison. More... | |
size_t | make_sort_key (uchar *to, size_t length, size_t trunc_pos) const final |
Writes a copy of the current value in the record buffer, suitable for sorting using byte-by-byte comparison. More... | |
uint32 | pack_length () const final |
uint32 | pack_length_no_ptr () const |
Return the packed length without the pointer size added. More... | |
uint | row_pack_length () const final |
uint32 | max_data_length () const final |
Get the maximum size of the data in packed format. More... | |
size_t | get_field_buffer_size () |
void | store_length (uchar *i_ptr, uint i_packlength, uint32 i_number) |
void | store_length (uint32 number) |
uint32 | data_length (ptrdiff_t row_offset=0) const final |
uint32 | get_length (ptrdiff_t row_offset=0) const |
uint32 | get_length (const uchar *ptr, uint packlength) const |
uint32 | get_length (const uchar *ptr_arg) const |
const uchar * | get_blob_data () const |
Get a const pointer to the BLOB data of this field. More... | |
uchar * | get_blob_data (ptrdiff_t row_offset=0) |
Get a non-const pointer to the BLOB data of this field. More... | |
const uchar * | data_ptr () const final |
Get a const pointer to the BLOB data of this field. More... | |
void | set_ptr (const uchar *length, const uchar *data) |
void | set_ptr_offset (ptrdiff_t ptr_diff, uint32 length, const uchar *data) |
void | set_ptr (uint32 length, const uchar *data) |
size_t | get_key_image (uchar *buff, size_t length, imagetype type) const override |
void | set_key_image (const uchar *buff, size_t length) final |
void | sql_type (String &str) const override |
bool | copy () |
Field_blob * | clone (MEM_ROOT *mem_root) const override |
Makes a shallow copy of the Field object. More... | |
uchar * | pack (uchar *to, const uchar *from, size_t max_length) const final |
Pack the field into a format suitable for storage and transfer. More... | |
uchar * | pack_with_metadata_bytes (uchar *to, const uchar *from, uint max_length) const final |
This function does the same thing as pack(), except for the difference that max_length does not mean the number of bytes in the output, but the maximum field length from the input (which must be exactly field->max_field_length()). More... | |
const uchar * | unpack (uchar *, const uchar *from, uint param_data) final |
Unpack a blob field from row data. More... | |
uint | max_packed_col_length () const final |
This is a wrapper around pack_length() used by filesort() to determine how many bytes we need for packing "addon fields". More... | |
void | mem_free () final |
bool | has_charset () const override |
uint32 | max_display_length () const final |
maximum possible display length for blob. More... | |
uint32 | char_length () const override |
maximum possible character length for blob. More... | |
bool | copy_blob_value (MEM_ROOT *mem_root) |
This function creates a separate copy of blob value. More... | |
uint | is_equal (const Create_field *new_field) const override |
Whether a field being created is type-compatible with an existing one. More... | |
bool | is_text_key_type () const final |
void | set_keep_old_value (bool old_value_flag) |
Mark that the BLOB stored in value should be copied before updating it. More... | |
void | keep_old_value () |
Save the current BLOB value to avoid that it gets overwritten. More... | |
void | store_in_allocated_space (const char *from, uint32 length) |
Use to store the blob value into an allocated space. More... | |
bool | backup_blob_field () |
Backup data stored in 'value' into the backup_value. More... | |
void | restore_blob_backup () |
Restore backup value. More... | |
Public Member Functions inherited from Field_longstr | |
Field_longstr (uchar *ptr_arg, uint32 len_arg, uchar *null_ptr_arg, uchar null_bit_arg, uchar auto_flags_arg, const char *field_name_arg, const CHARSET_INFO *charset_arg) | |
type_conversion_status | store_decimal (const my_decimal *d) override |
Decimal representation of Field_str. More... | |
bool | is_updatable () const final |
Checks whether a string field is part of write_set. More... | |
Public Member Functions inherited from Field_str | |
Field_str (uchar *ptr_arg, uint32 len_arg, uchar *null_ptr_arg, uchar null_bit_arg, uchar auto_flags_arg, const char *field_name_arg, const CHARSET_INFO *charset) | |
Item_result | result_type () const override |
Item_result | numeric_context_result_type () const final |
Returns Item_result type of a field when it appears in numeric context such as: SELECT time_column + 1; SELECT SUM(time_column); Examples: More... | |
uint | decimals () const override |
void | make_send_field (Send_field *field) const override |
Populates a Send_field object with metadata about the column represented by this Field object. More... | |
uint | repertoire () const final |
const CHARSET_INFO * | charset () const override |
void | set_charset (const CHARSET_INFO *charset_arg) |
void | set_field_length (uint32 length) final |
enum Derivation | derivation () const final |
void | set_derivation (enum Derivation derivation_arg) final |
bool | binary () const override |
bool | str_needs_quotes () const final |
void | add_to_cost (CostOfItem *cost) const override |
Update '*cost' with the fact that this Field is accessed. More... | |
Public Member Functions inherited from Field | |
Field (const Field &)=default | |
void | operator= (Field &)=delete |
bool | has_insert_default_general_value_expression () const |
Checks if the field is marked as having a general expression to generate default values. More... | |
bool | has_insert_default_datetime_value_expression () const |
Checks if the field is marked as having a datetime value expression to generate default values on inserts. More... | |
bool | has_update_default_datetime_value_expression () const |
Checks if the field is marked as having a datetime value expression to generate default values on updates. More... | |
bool | has_insert_default_constant_expression () const |
Checks if the field is marked as having a constant expression to generate default values. More... | |
uchar * | get_null_ptr () |
bool | is_flag_set (unsigned flag) const |
void | set_flag (unsigned flag) |
void | clear_flag (unsigned flag) |
uint32 | all_flags () const |
virtual bool | is_wrapper_field () const |
If true, it's a Create_field_wrapper (a sub-class of Field used during CREATE/ALTER that we mustn't cast to other sub-classes of Field that aren't on a direct path of inheritance, e.g. More... | |
virtual bool | is_unsigned () const |
Whether the field is signed or not. More... | |
bool | is_gcol () const |
bool | is_virtual_gcol () const |
void | set_hidden (dd::Column::enum_hidden_type hidden) |
Sets the hidden type for this field. More... | |
dd::Column::enum_hidden_type | hidden () const |
bool | is_hidden () const |
bool | is_hidden_by_system () const |
bool | is_hidden_by_user () const |
bool | is_field_for_functional_index () const |
Field (uchar *ptr_arg, uint32 length_arg, uchar *null_ptr_arg, uchar null_bit_arg, uchar auto_flags_arg, const char *field_name_arg) | |
This is used as a table name when the table structure is not set up. More... | |
virtual | ~Field ()=default |
void | reset_warnings () |
void | set_tmp_nullable () |
Turn on temporary nullability for the field. More... | |
void | reset_tmp_nullable () |
Turn off temporary nullability for the field. More... | |
void | reset_tmp_null () |
Reset temporary NULL value for field. More... | |
void | set_tmp_null () |
Set field to temporary value NULL. More... | |
bool | is_tmp_nullable () const |
bool | is_tmp_null () const |
virtual type_conversion_status | store_packed (longlong nr) |
Store a temporal value in packed longlong format into a field. More... | |
virtual type_conversion_status | store_time (MYSQL_TIME *ltime, uint8 dec_arg) |
Store MYSQL_TIME value with the given amount of decimal digits into a field. More... | |
type_conversion_status | store_time (MYSQL_TIME *ltime) |
Store MYSQL_TYPE value into a field when the number of fractional digits is not important or is not know. More... | |
type_conversion_status | store (const char *to, size_t length, const CHARSET_INFO *cs, enum_check_fields check_level) |
virtual longlong | val_time_temporal () const |
Returns TIME value in packed longlong format. More... | |
virtual longlong | val_date_temporal () const |
Returns DATE/DATETIME value in packed longlong format. More... | |
virtual longlong | val_time_temporal_at_utc () const |
virtual longlong | val_date_temporal_at_utc () const |
longlong | val_temporal_by_field_type () const |
Returns "native" packed longlong representation of a TIME or DATE/DATETIME field depending on field type. More... | |
String * | val_str (String *str) const |
String * | val_int_as_str (String *val_buffer, bool unsigned_flag) const |
Interpret field value as an integer but return the result as a string. More... | |
virtual Item_result | cmp_type () const |
virtual Item_result | cast_to_int_type () const |
bool | gcol_expr_is_equal (const Create_field *field) const |
Check whether generated columns' expressions are the same. More... | |
virtual bool | eq (const Field *field) const |
virtual bool | eq_def (const Field *field) const |
virtual uint32 | pack_length_in_rec () const |
virtual bool | compatible_field_size (uint metadata, Relay_log_info *, uint16, int *order) const |
Check to see if field size is compatible with destination. More... | |
virtual uint | pack_length_from_metadata (uint field_metadata) const |
int | save_field_metadata (uchar *first_byte) |
virtual type_conversion_status | reset () |
virtual bool | get_timestamp (my_timeval *tm, int *warnings) const |
Returns a UTC component in struct timeval format. More... | |
virtual void | store_timestamp (const my_timeval *) |
Stores a timestamp value in timeval format in a field. More... | |
virtual void | set_default () |
void | evaluate_insert_default_function () |
Evaluates the INSERT default function and stores the result in the field. More... | |
void | evaluate_update_default_function () |
Evaluates the UPDATE default function, if one exists, and stores the result in the record buffer. More... | |
virtual bool | zero_pack () const |
virtual enum_field_types | real_type () const |
virtual enum_field_types | binlog_type () const |
int | cmp (const uchar *str) const |
virtual int | cmp_offset (ptrdiff_t row_offset) const |
virtual int | cmp_binary_offset (ptrdiff_t row_offset) const |
bool | is_null (ptrdiff_t row_offset=0) const |
Check whether the full table's row is NULL or the Field has value NULL. More... | |
bool | is_real_null (ptrdiff_t row_offset=0) const |
Check whether the Field has value NULL (temporary or actual). More... | |
bool | is_null_in_record (const uchar *record) const |
Check if the Field has value NULL or the record specified by argument has value NULL for this Field. More... | |
void | set_null (ptrdiff_t row_offset=0) |
Set field to value NULL. More... | |
void | set_notnull (ptrdiff_t row_offset=0) |
Set field to value NOT NULL. More... | |
type_conversion_status | check_constraints (int mysql_errno) |
Check NOT NULL constraint on the field after temporary nullability is disabled. More... | |
void | set_check_for_truncated_fields (enum_check_fields check_for_truncated_fields) |
Remember the value of THD::check_for_truncated_fields to handle possible NOT-NULL constraint errors after BEFORE-trigger execution is finished. More... | |
bool | is_nullable () const |
uint | null_offset (const uchar *record) const |
uint | null_offset () const |
void | set_null_ptr (uchar *p_null_ptr, uint p_null_bit) |
virtual bool | optimize_range (uint idx, uint part) const |
Whether this field can be used for index range scans when in the given keypart of the given index. More... | |
virtual bool | can_be_compared_as_longlong () const |
virtual Field * | new_field (MEM_ROOT *root, TABLE *new_table) const |
Field * | new_field (MEM_ROOT *root, TABLE *new_table, uchar *new_ptr, uchar *new_null_ptr, uint new_null_bit) const |
virtual Field * | new_key_field (MEM_ROOT *root, TABLE *new_table, uchar *new_ptr, uchar *new_null_ptr, uint new_null_bit) const |
Field * | new_key_field (MEM_ROOT *root, TABLE *new_table, uchar *new_ptr) const |
void | move_field (uchar *ptr_arg, uchar *null_ptr_arg, uchar null_bit_arg) |
virtual void | move_field_offset (ptrdiff_t ptr_diff) |
virtual void | get_image (uchar *buff, size_t length, const CHARSET_INFO *) const |
virtual void | set_image (const uchar *buff, size_t length, const CHARSET_INFO *) |
longlong | val_int_offset (ptrdiff_t row_offset) |
longlong | val_int (uchar *new_ptr) |
String * | val_str (String *str, uchar *new_ptr) |
virtual bool | send_to_protocol (Protocol *protocol) const |
Send the value of this field over the protocol using the correct Protocol::store*() function which matches the type of the field. More... | |
uchar * | pack (uchar *to) const |
const uchar * | unpack (const uchar *from) |
virtual bool | pack_diff (uchar **to, ulonglong value_options) const |
Write the field for the binary log in diff format. More... | |
uint | offset (uchar *record) const |
void | copy_data (ptrdiff_t src_record_offset) |
virtual bool | get_date (MYSQL_TIME *ltime, my_time_flags_t fuzzydate) const |
virtual bool | get_time (MYSQL_TIME *ltime) const |
const CHARSET_INFO * | charset_for_protocol () const |
virtual const CHARSET_INFO * | sort_charset () const |
bool | set_warning (Sql_condition::enum_severity_level level, unsigned int code, int cut_increment) |
Produce warning or note about data saved into field. More... | |
bool | set_warning (Sql_condition::enum_severity_level level, uint code, int cut_increment, const char *view_db, const char *view_name) |
Produce warning or note about data saved into field. More... | |
bool | warn_if_overflow (int op_result) |
Process decimal library return codes and issue warnings for overflow and truncation. More... | |
virtual void | init (TABLE *table_arg) |
longlong | convert_decimal2longlong (const my_decimal *val, bool unsigned_flag, bool *has_overflow) |
Conversion from decimal to longlong. More... | |
virtual geometry_type | get_geometry_type () const |
void | dbug_print () const |
ha_storage_media | field_storage_type () const |
void | set_storage_type (ha_storage_media storage_type_arg) |
column_format_type | column_format () const |
void | set_column_format (column_format_type column_format_arg) |
virtual type_conversion_status | validate_stored_val (THD *thd) |
virtual void | hash (ulong *nr, ulong *nr2) const |
virtual ulonglong | get_max_int_value () const |
Get the upper limit of the MySQL integral and floating-point type. More... | |
const uchar * | field_ptr () const |
Return a const pointer to where the field is stored in the record buffer. More... | |
uchar * | field_ptr () |
Return a pointer to where the field is stored in the record buffer. More... | |
void | set_field_ptr (uchar *ptr_arg) |
bool | is_part_of_actual_key (THD *thd, uint cur_index, KEY *cur_index_info) const |
Check whether field is part of the index taking the index extensions flag into account. More... | |
Key_map | get_covering_prefix_keys () const |
Get covering prefix keys. More... | |
virtual bool | is_array () const |
Whether the field is a typed array. More... | |
virtual uint32 | get_length_bytes () const |
Return number of bytes the field's length takes. More... | |
bool | handle_old_value () const |
Whether field's old valued have to be handled. More... | |
virtual void | set_field_index (uint16 field_index) |
Sets field index. More... | |
uint16 | field_index () const |
Returns field index. More... | |
Protected Member Functions | |
void | store_ptr_and_length (const char *from, uint32 length) |
Store ptr and length. More... | |
Protected Member Functions inherited from Field_longstr | |
type_conversion_status | check_string_copy_error (const char *well_formed_error_pos, const char *cannot_convert_error_pos, const char *from_end_pos, const char *end, bool count_spaces, const CHARSET_INFO *cs) |
Report "not well formed" or "cannot convert" error after storing a character string info a field. More... | |
Protected Member Functions inherited from Field | |
uchar * | pack_int16 (uchar *to, const uchar *from, size_t max_length) const |
const uchar * | unpack_int16 (uchar *to, const uchar *from) const |
uchar * | pack_int24 (uchar *to, const uchar *from, size_t max_length) const |
const uchar * | unpack_int24 (uchar *to, const uchar *from) const |
uchar * | pack_int32 (uchar *to, const uchar *from, size_t max_length) const |
const uchar * | unpack_int32 (uchar *to, const uchar *from) const |
uchar * | pack_int64 (uchar *to, const uchar *from, size_t max_length) const |
const uchar * | unpack_int64 (uchar *to, const uchar *from) const |
Static Protected Member Functions | |
static uchar * | get_blob_data (const uchar *position) |
Get the BLOB data pointer stored at the specified position in the record buffer. More... | |
Protected Attributes | |
uint | packlength |
The number of bytes used to represent the length of the blob. More... | |
String | value |
The 'value'-object is a cache fronting the storage engine. More... | |
Protected Attributes inherited from Field_str | |
const CHARSET_INFO * | field_charset |
enum Derivation | field_derivation |
Protected Attributes inherited from Field | |
uchar * | ptr |
Holds the position to the field in record. More... | |
Private Member Functions | |
virtual type_conversion_status | store_internal (const char *from, size_t length, const CHARSET_INFO *cs) |
type_conversion_status | store_to_mem (const char *from, size_t length, const CHARSET_INFO *cs, size_t max_length, Blob_mem_storage *) |
Copy value to memory storage. More... | |
int | do_save_field_metadata (uchar *first_byte) const override |
Save the field metadata for blob fields. More... | |
Private Attributes | |
String | old_value |
In order to support update of virtual generated columns of blob type, we need to allocate the space blob needs on server for old_row and new_row respectively. More... | |
bool | m_keep_old_value |
Whether we need to move the content of 'value' to 'old_value' before updating the BLOB stored in 'value'. More... | |
String | m_blob_backup |
Backup String for table's blob fields. More... | |
bool | m_uses_backup {false} |
Whether the field uses table's backup value storage. More... | |
Additional Inherited Members | |
Public Types inherited from Field | |
enum | enum_auto_flags { NONE = 0 , NEXT_NUMBER = 1 , DEFAULT_NOW = 2 , ON_UPDATE_NOW = 4 , GENERATED_FROM_EXPRESSION = 8 } |
Flags for Field::auto_flags / Create_field::auto_flags bitmaps. More... | |
enum | geometry_type { GEOM_GEOMETRY = 0 , GEOM_POINT = 1 , GEOM_LINESTRING = 2 , GEOM_POLYGON = 3 , GEOM_MULTIPOINT = 4 , GEOM_MULTILINESTRING = 5 , GEOM_MULTIPOLYGON = 6 , GEOM_GEOMETRYCOLLECTION = 7 } |
enum | imagetype { itRAW , itMBR } |
Static Public Member Functions inherited from Field | |
static bool | type_can_have_key_part (enum_field_types) |
Check whether a field type can be partially indexed by a key. More... | |
static enum_field_types | field_type_merge (enum_field_types, enum_field_types) |
Return type of which can carry value of both given types in UNION result. More... | |
static Item_result | result_merge_type (enum_field_types) |
Detect Item_result by given field type of UNION merge result. More... | |
Public Attributes inherited from Field_str | |
uint32 | char_length_cache |
Public Attributes inherited from Field | |
TABLE * | table |
Pointer to TABLE object that owns this field. More... | |
const char * | orig_db_name {nullptr} |
Pointer to original database name, only non-NULL for a temporary table. More... | |
const char * | orig_table_name {nullptr} |
Pointer to original table name, only non-NULL for a temporary table. More... | |
const char ** | table_name |
const char * | field_name |
LEX_CSTRING | comment |
Key_map | key_start |
Key_map | part_of_key |
Keys that includes this field except of prefix keys. More... | |
Key_map | part_of_prefixkey |
Prefix keys. More... | |
Key_map | part_of_sortkey |
Key_map | part_of_key_not_extended |
All keys that include this field, but not extended by the storage engine to include primary key columns. More... | |
uint32 | field_length |
uchar | null_bit |
uchar | auto_flags |
Bitmap of flags indicating if field value is auto-generated by default and/or on update, and in which way. More... | |
bool | is_created_from_null_item |
If true, this field was created in create_tmp_field_from_item from a NULL value. More... | |
bool | m_indexed |
True if this field belongs to some index (unlike part_of_key, the index might have only a prefix). More... | |
LEX_CSTRING | m_engine_attribute = EMPTY_CSTR |
LEX_CSTRING | m_secondary_engine_attribute = EMPTY_CSTR |
Value_generator * | gcol_info {nullptr} |
bool | stored_in_db |
Indication that the field is physically stored in tables rather than just generated on SQL queries. More... | |
Value_generator * | m_default_val_expr {nullptr} |
Holds the expression to be used to generate default values. More... | |
Static Public Attributes inherited from Field | |
static constexpr size_t | MAX_VARCHAR_WIDTH {65535} |
static constexpr size_t | MAX_TINY_BLOB_WIDTH {255} |
static constexpr size_t | MAX_SHORT_BLOB_WIDTH {65535} |
static constexpr size_t | MAX_MEDIUM_BLOB_WIDTH {16777215} |
static constexpr size_t | MAX_LONG_BLOB_WIDTH {4294967295} |
Static Protected Attributes inherited from Field | |
static uchar | dummy_null_buffer = ' ' |
Field_blob::Field_blob | ( | uchar * | ptr_arg, |
uchar * | null_ptr_arg, | ||
uchar | null_bit_arg, | ||
uchar | auto_flags_arg, | ||
const char * | field_name_arg, | ||
TABLE_SHARE * | share, | ||
uint | blob_pack_length, | ||
const CHARSET_INFO * | cs | ||
) |
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inline |
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inline |
Copy static information and reset dynamic information.
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explicit |
bool Field_blob::backup_blob_field | ( | ) |
Backup data stored in 'value' into the backup_value.
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overridevirtual |
maximum possible character length for blob.
This method is used in Item_field::set_field to calculate max_length for Item.
For example: CREATE TABLE t2 SELECT CONCAT(tinyblob_utf8_column) FROM t1; must create a "VARCHAR(255) CHARACTER SET utf8" column.
Reimplemented from Field.
Reimplemented in Field_typed_array.
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inlineoverridevirtual |
Makes a shallow copy of the Field object.
mem_root | MEM_ROOT to use for memory allocation. |
NULL | If memory allocation failed. |
Implements Field.
Reimplemented in Field_geom, Field_json, and Field_typed_array.
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overridevirtual |
Reimplemented from Field.
Reimplemented in Field_json.
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finalvirtual |
Reimplemented from Field.
bool Field_blob::copy | ( | ) |
bool Field_blob::copy_blob_value | ( | MEM_ROOT * | mem_root | ) |
This function creates a separate copy of blob value.
[in] | mem_root | mem_root that is used to allocate memory for 'copy_of_value'. |
false | Success |
true | Failure |
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inlinefinalvirtual |
Reimplemented from Field.
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inlinefinalvirtual |
Get a const pointer to the BLOB data of this field.
Reimplemented from Field.
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overrideprivatevirtual |
Save the field metadata for blob fields.
Saves the pack length in the first byte of the field metadata array at index of *metadata_ptr.
metadata_ptr | First byte of field metadata |
Reimplemented from Field.
Reimplemented in Field_typed_array.
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inline |
Get a const pointer to the BLOB data of this field.
Get the BLOB data pointer stored at the specified position in the record buffer.
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inline |
Get a non-const pointer to the BLOB data of this field.
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inline |
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overridevirtual |
Reimplemented from Field.
Reimplemented in Field_typed_array.
uint32 Field_blob::get_length | ( | ptrdiff_t | row_offset = 0 | ) | const |
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inlineoverridevirtual |
Reimplemented from Field.
Reimplemented in Field_json.
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overridevirtual |
Whether a field being created is type-compatible with an existing one.
Used by the ALTER TABLE code to evaluate whether the new definition of a table is compatible with the old definition so that it can determine if data needs to be copied over (table data change). Constraints and generation clause (default value, generation expression) are not checked by this function.
new_field | new field definition from alter. |
IS_EQUAL_YES | if there is no change. |
IS_EQUAL_PACK_LENGTH | if the data are unchanged, but the length requirements have changed |
IS_EQUAL_NO | if there is an incompatible change requiring copy. |
Reimplemented from Field_str.
Reimplemented in Field_geom, and Field_json.
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inlinefinalvirtual |
Reimplemented from Field.
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inline |
Save the current BLOB value to avoid that it gets overwritten.
This is used when updating virtual generated columns that are BLOBs. Some storage engines require that we have both the old and new BLOB value for virtual generated columns that are indexed in order for the storage engine to be able to maintain the index. This function will transfer the buffer storing the current BLOB value from 'value' to 'old_value'. This avoids that the current BLOB value is over-written when the new BLOB value is saved into this field.
The reason this requires special handling when updating/deleting virtual columns of BLOB type is that the BLOB value is not known to the storage engine. For stored columns, the "old" BLOB value is read by the storage engine, Field_blob is made to point to the engine's internal buffer; Field_blob's internal buffer (Field_blob::value) isn't used and remains available to store the "new" value. For virtual generated columns, the "old" value is written directly into Field_blob::value when reading the record to be updated/deleted. This is done in update_generated_read_fields(). Since, in this case, the "old" value already occupies the place to store the "new" value, we must call this function before we write the "new" value into Field_blob::value object so that the "old" value does not get over-written. The table->record[1] buffer will have a pointer that points to the memory buffer inside old_value. The storage engine will use table->record[1] to read the old value for the BLOB and use table->record[0] to read the new value.
This function must be called before we store the new BLOB value in this field object.
Reimplemented from Field.
Reimplemented in Field_typed_array.
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overridevirtual |
Reimplemented from Field.
Reimplemented in Field_typed_array.
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inlineoverridevirtual |
Reimplemented from Field.
Reimplemented in Field_typed_array.
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inlineoverridevirtual |
Reimplemented from Field.
Reimplemented in Field_geom.
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overridevirtual |
Writes a copy of the current value in the record buffer, suitable for sorting using byte-by-byte comparison.
Integers are always in big-endian regardless of hardware architecture. At most length bytes are written into the buffer.
buff | The buffer, assumed to be at least length bytes. |
length | Number of bytes to write. |
The | number of bytes actually written. |
Implements Field.
Reimplemented in Field_json, Field_typed_array, Field_json, Field_typed_array, and Field_typed_array.
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finalvirtual |
Writes a copy of the current value in the record buffer, suitable for sorting using byte-by-byte comparison.
Integers are always in big-endian regardless of hardware architecture. At most length bytes are written into the buffer. Field_string, Field_varstring and Field_blob classes are truncated after pos number of characters.
buff | The buffer, assumed to be at least length bytes. |
length | Number of bytes to write. |
trunc_pos | Number of characters which should be included before truncation. |
The | number of bytes actually written. |
Reimplemented from Field.
Reimplemented in Field_json, and Field_typed_array.
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inlineoverridevirtual |
Reimplemented from Field.
Reimplemented in Field_geom, and Field_typed_array.
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inlinefinalvirtual |
Get the maximum size of the data in packed format.
Reimplemented from Field_longstr.
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finalvirtual |
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finalvirtual |
This is a wrapper around pack_length() used by filesort() to determine how many bytes we need for packing "addon fields".
Reimplemented from Field.
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inlinefinalvirtual |
Reimplemented from Field.
Pack the field into a format suitable for storage and transfer.
To implement packing functionality, only the virtual function should be overridden. The other functions are just convenience functions and hence should not be overridden.
The actual format is opaque and will vary between types of Field (it is meant to be unpacked by unpack(), but be aware that it is used among others in the replication log, so you cannot change it without incurring a format break.
max_length
characters.to | Pointer to memory area where representation of field should be put. |
from | Pointer to memory area where record representation of field is stored, typically field->field_ptr(). |
max_length | Available space in “to”, in bytes. pack() will not write more bytes than this; if the field is too short, the contents are not unpackable by unpack(). (It is nominally supposed to be a prefix of what would have been written with a full buffer, ie., the same as packing and then truncating the output, but not all Field classes follow this.) |
Reimplemented from Field.
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inline |
Return the packed length without the pointer size added.
This is used to determine the size of the actual data in the row buffer.
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finalvirtual |
This function does the same thing as pack(), except for the difference that max_length does not mean the number of bytes in the output, but the maximum field length from the input (which must be exactly field->max_field_length()).
The difference is currently only relevant for Field_blob, but can be summed up as follows:
Reimplemented from Field.
void Field_blob::restore_blob_backup | ( | ) |
Restore backup value.
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inlinefinalvirtual |
Reimplemented from Field.
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inline |
Mark that the BLOB stored in value should be copied before updating it.
When updating virtual generated columns we need to keep the old 'value' for BLOBs since this can be needed when the storage engine does the update. During read of the record the old 'value' for the BLOB is evaluated and stored in 'value'. This function is to be used to specify that we need to copy this BLOB 'value' into 'old_value' before we compute the new BLOB 'value'. For more information
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finalvirtual |
Reimplemented from Field.
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overridevirtual |
Implements Field.
Reimplemented in Field_geom, Field_typed_array, and Field_json.
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overridevirtual |
Implements Field_str.
Reimplemented in Field_geom, Field_geom, Field_json, and Field_typed_array.
type_conversion_status Field_blob::store | ( | const Field * | from | ) |
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overridevirtual |
Store double value in Field_string or Field_varstring.
Pretty prints double number into field_length characters buffer.
nr | number |
Reimplemented from Field_str.
Reimplemented in Field_geom, Field_geom, Field_json, and Field_typed_array.
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overridevirtual |
Implements Field_str.
Reimplemented in Field_geom, Field_geom, Field_json, and Field_typed_array.
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inline |
Use to store the blob value into an allocated space.
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privatevirtual |
Reimplemented in Field_geom.
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inline |
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inlineprotected |
Store ptr and length.
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private |
Copy value to memory storage.
Store a blob value to memory storage.
from | the string value to store. |
length | length of the string value. |
cs | character set of the string value. |
max_length | Cut at this length safely (multibyte aware). |
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inlineoverridevirtual |
Implements Field.
Reimplemented in Field_geom, Field_json, and Field_typed_array.
Unpack a blob field from row data.
This method is used to unpack a blob field from a master whose size of the field is less than that of the slave. Note: This method is included to satisfy inheritance rules, but is not needed for blob fields. It simply is used as a pass-through to the original unpack() method for blob fields.
from | Source of the data |
param_data | The "metadata", as stored in the Table_map_log_event for this field. This metadata is the number of bytes used to represent the length of the blob (1, 2, 3, or 4). |
Reimplemented from Field.
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overridevirtual |
Implements Field.
Reimplemented in Field_json.
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overridevirtual |
Implements Field.
Reimplemented in Field_json.
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overridevirtual |
Implements Field.
Reimplemented in Field_json.
Implements Field.
Reimplemented in Field_json.
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private |
Backup String for table's blob fields.
UPDATE of a virtual field (for index update) requires two values to be kept at the same time - 'new' and 'old' since SE (InnoDB) doesn't know the latter. In the case when there was an indexed record, it got deleted and When INSERT inserts into an index a record that coincides with a previously deleted one, InnoDB needs to recalculate value that was deleted in order to properly insert the new one. When two above overlap, a field have to keep 3 different values at the same time - 'new', 'old' and 'deleted'. This backup_value is used by
Also used for set operation hashing: we need to compare the new and the existing record with the same hash.
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private |
Whether we need to move the content of 'value' to 'old_value' before updating the BLOB stored in 'value'.
This needs to be done for updates of BLOB columns that are virtual since the storage engine does not have its own copy of the old 'value'. This variable is set to true when we read the data into 'value'. It is reset when we move 'value' to 'old_value'. The purpose of having this is to avoid that we do the move operation from 'value' to 'old_value' more than one time per record. Currently, this variable is introduced because the following call in sql_data_change.cc: \/**
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private |
Whether the field uses table's backup value storage.
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private |
In order to support update of virtual generated columns of blob type, we need to allocate the space blob needs on server for old_row and new_row respectively.
This variable is used to record the allocated blob space for old_row.
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protected |
The number of bytes used to represent the length of the blob.
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protected |
The 'value'-object is a cache fronting the storage engine.